The city of Austin threw a massive Halloween party on October 31st, 2012. Over two thousand people became seriously ill with what was assumed to be mass food poisoning. Hospitals were overwhelmed, with some victims being sent to Houston or Dallas hospitals. Over one hundred people died. Some of the victims began to display amazing new abilities, such as immunity to fire or impenetrable skin.
After a few miserable days in the hospital, on November 4th the illness simply vanished from all of the victims. No diagnosis was ever made. No treatment appears to have been effective at alleviating any of the symptoms. All of the patients were to be discharged on November 5th.
And then things got weird.